The RAND research team focused on Cost Adjustment Sheets (CASs) and their role in the Navy's Flying Hour Program (FHP) budgeting process. In recent years, most CASs have increased the FHP budget. In addition, CASs have been far more utilized by the F/A-18 program than by program offices for most other types of naval aircraft. RAND assessed the contribution of CASs to the accuracy of FHP budgets and whether CAS usage is correlated with expenditure-per-flying-hour growth. RAND also examined why CASs have been used more heavily by the F/A-18 program.